When I'm an engineer at a festival working for one of the bands and I see a 'stereo' sub set up I always insist on having my console setup off-center of the PA. As I see it anybody can make it sound decent when mixing on-center. The challenge becomes a reality when trying to make it sound decent for the other 90% of audience (not near or on center) when stuck in this situation. People think I'm crazy requesting an off-center placement. 'Oh, well.' I say to them. Great, informative video as always, Dave.
Suspect this will be a very useful series, optimal subwoofer placement is something that is not naturally intuitive even to those who work in sound and something i regularly see and hear implemented poorly. Having a software and mathematical model to validate placement is always going to be a smaart approach, one of the many tools at our disposal in the modern era as a live sound tech it would be crazy to ignore.
I just want to share this video with every technical director and production manager that has looked at me like I'm a moron for not wanting to place subs either side of the stage. Or for even just suggesting there are other options for subs that allow for a better result for the majority of the audience. I get that sometimes the easiest placement for subs is either side of stage and that just where the majority of people expect them to go. But it is a shit position for them and with a bit of planning better solutions can always be found. Thanks so much for this series. We need resources like this to be out there in order to change the status quo of people's understanding of sound design principles and just because it's always been done a certain way doesn't mean that that's the best way. Or the only way............ Cheers
As someone building a custom sound system (with a few friends) designed for heavy electronic bass music, this series is right up my alley! So far we've got four 18" subs for our version 1.0, but I suspect we will double that at some point. Looking forward to the rest of the series!
Never knew how much a horizontal line cancels out to the side. I go to heavy dubstep shows and all of them that have more than just the venue's sound system just have a line across the front. And I love it, because I'm always on the guard rail getting my bones vibrated. But I did notice at the one arena show I went to where I was up in the stands but free to roam. off to the sides it was pretty quiet but when I went to the center of the back of the arena it was still incredibly loud and more than what my phone mic could pick up clearly. Excited to see part 2
These deep nulls are really well defined outdoors, or in acoustically large environments. The 80's ushered in outdoor amphitheaters, and my first mix in such a venue I experienced this deep null adjacent to the actual FOH mix position ... still within the barrier corral! Blew my mind how significant it was. I understood it, sure, but seriously, the energy simply nulls. Outdoors, absent of boundary interactions, those patterns are well defined. Better yet; casino center bar, small live music stage. Typically I see them use a sub and top per side. Damn it's mind blowing the physics lessen you get by simply walking around. A center bar, in the middle of a big casino. Ceiling 40 feet or so and no boundaries for hundreds of feet in any direction. You can walk all around ... behind the stage, etc. The summation interactions are so vividly clear ... likely the best case scenario for experiencing such interactions in situ.
Agreed, I remember playing a casino ballroom somewhere with Soundgarden that was super well sound damped. And yes, could totally hear all the sub array flaws and assets.
I do a small festival in Oklahoma. A fairly large tent and coverage is always an issue. Thank you so much for your information and time you put into these videos. they are a huge help and highly informative
Thanks for showing this! The system for my venue was designed and installed years ago with a DSP that handles all the mono fills and crossover for the subs. The subs are part of the only stereo element, but we've always put bass elements on mono for the sake of coverage. But we have anomalous results in different frequencies where I end up with bassy resonances in parts of the room that don't seem to come from any single instrument while other parts of the room can be relatively bass-free. We are due for a new system in the next year where I'm going to work with the engineer to come up with a better sub solution. Meanwhile, I may try panning some bass elements. While the coverage of individual instruments might not be uniform, I think what we gain in clarity and lose in cancellation will more than make up for it. I look forward to seeing the rest of the series!
Thank you as always for the great resource! The visual representation of the sub output was helpful. I've applied principles I've learned from you in my mixes and the response from clients and audiences has been very positive.
I found it very interesting to consider the subwoofers response way above the crossover frequency. If we take 60dB+ as a practical value for "total" attenuation, then when you use a 24dB/octave low-pass filter at 100Hz, you're gonna get energy from the subs even up to 2.5 octaves higher than that (2.5*24dB = 60dB). So the real limit at which the subs are no longer producing any significant sound energy would be close to 600Hz! (2.5 octaves from 100Hz). So it makes total sense to care about their response beyond the crossover frequency. Thanks for the video
Super excited about this series. It's great to see the old "bass cannon" blog posts come to video form! This shows why it's so important to not only have a great system, but also have it set up well. People may be biased towards and of the big names, be it L.acoustics, d&b etc. etc. but I'm pretty sure that most 'strong' opinions that formed are not based on speaker quality, but on the quality of the implementation they heard. If you don't have control over the setup, walk around (if possible) and get an impression on how it sounds throughout the audience. Wooden risers will also greatly skew your bass perception through tactility, so in the worst case you might be mixing in a bad power alley, while already "hearing" more bass because you're on a riser, resulting in the audience having no bass at all.
6 dual 18's in a cardio pattern center stacked. reverse the two center boxes. Hands down the best setup, put that in your program and see for yourself. The only real issue is the audience can power off the 2 middle boxes by reaching through the barrier lol!
That is a useful setup. And one of many to have in your solution set. It's good for even coverage and moderate reduction of sub on stage with a mono or close to mono subs sound. I prefer getting the bulk of the subs farther from center stage, having a more stereo sub setup. Also if possible, using increased distances between the front and rear subs in endfire and cardioid setups offer better rear cancellations than subs flipped backwards. I would say that gaining a diverse knowledge of the advantages and issues with various setups is preferable to having a single favorite best
Very much looking forward to the next installment into this subwoofer series. I've been playing around with systems I manage including my own with two single 18" enclosures. I've heard the cancelations across the listening area always be worse when the subs are apart. That in mind I've been working to keep them together. Even if they have to both be on one side. I've seen others share software screenshots similar to the ones you have here. I can hear what your showing us. Cool stuff. Now to learn about how to best utilize what I have at my disposal. I also wonder about best crossover frequency to transition to mains and so on. Especially when one or the other struggle to give output in that area... I'd imagine a large majority of people in position to provide, setup and run sound, are using low end and limited gear like myself. One to four subwoofer enclosures in the 1kw each power range. Keep the knowledge and experience stories flowing Dave. Much value in them.
In my particular venue, I do have 8 Rat subs across the front in a slight arc since the stage apron is curved. But the stage is as wide as the main floor, with the ends of the array only about 4 feet from each wall. So it covers pretty evenly in the room. However, since a good amount of energy is thrown onto the stage, some acts don't like that, though most don't mind. There's not really any room to do a more directional array unfortunately. The other downside is there's an area off too the side and 3 feet higher than the main floor that doesn't get much sub coverage. So for some shows, when they put people up there, additional subs need to be added to that area.
I think the only solution for reducing rear spill in my case would be to use a single box cardioid solution like EAW Otto or something similar. But hey, I"m a one person sound-army, so there's no budget for that ;-)
Another way to get around the summing & phase problems of a stereo pair of stacked subs is just pan stuff to one side, or even run a crossover or stereo spreader so that each side gets a different split of frequencies per instrument. The elephant in the room that makes the pretty plots rather inaccurate is... Group delay. Especially in bass reflex cabs.
I get into altering the mix and altering time delays and ways to predict that in video 4 of the series. First we look at what happens and ways to optimize arrays, then we look at optimizing processing and the mix
Super interesting behavior of the low end in those analyses. I had no idea it would do that but it makes sense the way you explain it all. I have experienced the holes but never put two and two together in any way. Super cool!
This is perfect thank you, my venue has an 8 sub array across a 16m stage with 3-4ft gaps between subs sideways, works well for center but it's a wide and deep venue so there are holes, interested to see more!
Looking forward to the rest of this series! Been trying to setup end fire and cardiod sub arrays and been trying to figure out how to make the calculations work for best possible results for a while now.
OR, could a cabinet be built that has a 'baffling maze' that ultimately exits through an opening in the BACk of the cab that would be timed (And perhaps slowed and muffled with foam or an absorbant material....or not) and then the cab would act as its own self-canceling sub? It could this only be done for one specific use in one specific venue? because they all have different gaping space behind, under and over the stage? And thank you so much for sharing your knowledge with us and your patients in considering my not-well articulated ideas!
For reproduction of a single sound, that could work. That challenge is that instruments radiate a vast array of sounds that are different in every direction. We know this because the sound changes depending on where we mic the instrument. When mic'ing a speaker we always just get a brighter, duller or more resonant version of the one sound or mix that it is reproducing. To recreate an instrument we need to radiate several or many different sound in different directions, like the real thing does. To do this we need several or many seperate signals and speakers.
7:38: yeah, I absolutely hate setups with subwoofers on the sides only. When the most common seats we tend to buy are in the back slightly off center, it sounds extremely harsh and boring with this setup! For instance, there’s a concert series in a park in my city, and the setup is always 8 d&b audiotechnik V series line arrays per side in the main hangs, and each one has a cluster of 3 b2-subs right below it on the ground. The sub in the center of each of these clusters is facing backward, and likely has some delay for a cardioid dispersion pattern. However, in order to get good bass, your view is either blocked by the sound & lighting booth (in the dead center of the lawn) or blocked by the structure of the stage on the side! Everywhere else, the bass sucks! There is a dead spot between around 10 and 30 degrees off center on each side, especially toward the back! Edit: important to know, the d&b b2-sub is a dual 18 inch, bandpass box. These are one of my favorite designs for a punchy sound.
You have many years of mix experience in arena's and different size venues with your vast array of mix experience. Have you spent anytime covering how to compensate for the bass tunnel or power alley that happens in smaller theaters underneath balcony's? I've seen people mix from on top of the balcony or out in front of a balcony on the lower floor. But never underneath, just has a concert spectator, I've always noticed more bass standing at the back of a theater underneath the balcony. Would be great to see what's happening with subs in a theater with a balcony computer simulated, if possible??
I do cover that and the videos are currently on the member side of the RU-vid channel I'm looking to clean them up and release them public at some point. Basically to solve that issue of having the same sound come out of multiple speakers is not send the same sound in multiple speakers that are spaced far apart
0:05 Oh, man, that looks like a Bassnectar NYE360 event. I once went to one with something like 3,000,000 Watts of driver power inside a sold-out arena of 30k people. I probably lost a percentage point of hearing at that set when, standing in the floor pit, I lost an earplug and got tired of manually plugging it.
Greensboro 2018 into 2019! Just before the world went crazy. I'm honored to meet ya! I'm on the electronics side professionally/by trade and a speaker hobbyist. At that time, I was building little
I was not expecting the center setup to beam-form nearly as much. I guess that should have been obvious...lol. We do festivals with a standard straight mono sub wall. I guess this good for our setup so we don't interfere with adjacent stages as much.
I worked in a venue where we had the 2 subs with masive combing. I was at an event being destroyed by low end i walked over to FOH and hardly anything. Ever since ive been looking for the best set up. It changes so much show to show and often comprises are thrust upon us by the venue.
Very inspirational Dave. I made the mistake of calling the horizontal dispersion points of subs as "Thunder Alley" but what it is called is power alley. However I never considered these node empties nor the energy on stage before watching this. I did however consider the option of splaying the subs so this doesn't happen. It was all in consideration of the audience but if so can we see a cancelation of undesirable sub energy on the stage as well. Just curious. Love your insight and knowhow and sound physics approach. Thank you.
What would happen if you put an array of subs in the very back of the room, and adjusted pahse: in/out/160 etc (Maybe based on time/distance from the subs at the stage....find a formula there) And then used those subs to either cancel or "draw out" frequencies that are not playing nice across the whole field? Am I making sense? I realize that there is very little new under the sun, but could you locate and "long lobes" of freqs and put a sub at the far end of them and create a phase cancellation to tame them? Or at that point are we just wastuing energy that could be better put to use elswehere and how?
Whenever you have a distance between sources reproducing the same signal, you get significant cancellations and issues. Also that back of the room is 100s of feet away so there will be time delay issues. People near the back will here sound too early if there is no delay and if delay is added, the sound from the speakers in the back will be super late for people more toward the front.
Why do festivals on flat ground not use large (10+) towers of subs to get the power without any of the lobing issues? So little attention (it seems) is ever paid to vertical coverage for subs (unlike tops). Admittedly the horizontal will be omni, causing issues on stage
In video 1 where I show the coverage of a single sube per side, that is the same as a vertical sub array on flat ground. I believe it is the 2nd prediction set, right after single sub. The big challenge with one sub per side or one tall line per side is the octave wide cancellation node just to the left and right of center.
Interesting video , and i can see youre modelling a direct radiator type subwoofer. Does anything change regarding the output patterns if theyre horn loaded or tapped horns specifically ? Im in the process of adding more cabinets to my system, ive typically ran 6 in a row at the front center, but am about to add another 4 per side. I had pictured the side cabs toed in and arc'd to have a focal point/zone, im starting to wonder if this would even be any good.
Various cab designs can be more or less directional, this pretty much shows worst case scenario because I haven't made any compensation for frequency response of the enclosure off axis other than what's in the software. I guess this would help with guidance in the preferred design and then using an enclosure that's more directional will help improve it further or could. As far as hornloaded versus tapped horn, I'm not aware of any directionality differences created by using a tapped horn. Whether you use the front of a speaker or the front and rear of a speaker combined together within the enclosure doesn't make much difference to dispersion and coverage as it should only impact frequency response and SPL level The exception would be if the front of the speaker is coming out of a different location on the enclosure than the rear of the speaker which would be create a directional box
@DaveRat that all makes perfect sense thankyou. I still haven't seen anyone simulate anything along the lines of the stereo stack combined with the center row. I can mentally figure it would be a summation of the two sims and would still have a few dips and peaks across the center but if they were positioned in a slight arc around the dance floor rather than away / wider, would this be more of less ideal to battle cancellations ? I will have the capacity to delay the side stacks relative to the center row only, and once the new side stacks are built I will absolutely play with delay settings. This is new territory for me , and I'm keen to get it nice n loud.
This can all be predicted with software to determine coverage. And it's not that hard to do what I did too hear what's going on if you want to take the time to do it
Why did the ev 4 fail? To this day, I haven't heard anything that could compare. Was it the requirement of amp power that killed it and why can't you modify them to be self powered like everything else is today?
Dave, once again you really help me. I’m in my forties but getting back in to live sound. I have custom built every PA system I own. Currently 4 18”s 12 15”s so every bit helps! Also is that software available somewhere? Love to experiment with it. Thanks for nerding out with your friends!!!
All that software is free! Download L-Acoustics soundvision. Learn it and use the sb28 or sb215 subs in the software. Also Meyer mapp is free and I believe it's online now.
And just an FYI, your my hero from Ohio. I have been on some of the same adventures as you starting out as a DJ in 6th grade to after high school and endeavoring in live sound through high school and beyond!!!
That would be super cool but also brings up an interesting complexity. How would you time the delay on those subs? Would each row of seats have a lightly longer delay so the subs align with the main sound system? If so, additive nature of all those delays would focus all the LF energy toward the back of the room. A massive complex endfire array that reduces subs for people close to the stage and I creases subs for those in the back. Or would all the subs be at 0ms which means that for people farther away they hear the subs before the main pa sound and the combined LF energy would be focused upwards.
@@DaveRat Yeah, that's a lot to consider lol. It would be fun to have the opportunity to experiment with the idea though. Perhaps if one could start with the room design itself to eliminate some obstacles. Would time delays and lowering output levels combined be a solution to a degree? Perhaps using very small cardioid subs facing upward combined with delay and lower outputs? Do you see any scenario where this approach could work? I was kinda joking, but if I ever did win the lottary, I would probably need to know this stuff haha! Cheers Dave! And Merry Christmas man! Hope you have a fantastic 2023!✌🤙👊
One question. Will the interference pattern go away if there are people in front of it? The way the waves are goind should be longer with people in the way and thery should mix. Is this true?
Meh, not really. Room reflections and obstacle like humans can soften the extreme peaks and nulls, but a wonky setup will always be more wonky than a smoother setup.
Yes. The dead spot occurs due to the same frequency being radiated from two places. The type of speaker makes no difference. It could be 8x10" svt cabs and would still happen.
What you see is the overlap of 2 sound sources recreating the same signal. If you reduce the overlap, the interference patterns will reduce. But does not matter what creates the sound. What matters is the freq responce and coverage. To stop the issues you need to either eliminate the overlaps in coverage or eliminate having more than one source recreating the same signal covering the same area.
I’ll be paying particular attention to the spaced pair of dual 18 subs when you get into delays and polarity reversals… I wish there was freeware for modelling - the world would sound better, because the tools are out there in terms of system processing, but we can’t easily model to predict where to start as far as system optimisation goes…or am I incorrect?
It looks like Dave is using L-Acoustics Soundvision and Meyer Sound MAPP. Both are free according to their websites. I haven't tried them, but they look pretty interesting
The software is free and double 18s will model in similar ways so you don't need to import, just use the most similar product made by the company and you should get the info you need.
Hey Bro is there a sub design that gives you better distance before fall off I use the SB850s trap design and the SB1000s long throw design I don't feel there's a difference in coverage
Not really but like a line array main pa, a long line of subs can focus energy at a far point and nearer points won't have max summation. Resulting in a less drastic drop off
Dual 18 subs are pretty common for clubs 500 capacity and up. We have sold loads and loads to churches, performing art centers, schools and more. Even smaller clubs will often have one or two.
Would this be considering the subs are firing the exact same frequency at the exact same time? If so, would your technique of panning kick drum and bass guitar inputs hard left and right help get rid of that combing?
Absolutely! You are already in the advanced phases. This is parts of the vid leading up to the panning and such. As a member,there is an extended hour long sub vid that covers all three of the vids in this series. Then also a vid about sending differing signals. There should be in the pro subwoofer playlist
Very cool and welcome! Will be doing a zoom chat this week. I know YT is a bit of a bummer to navigate Coachella and member exclusive playlists should have some stuff that is not public. And other stuff is smattered around
What about putting a subwoofer behind the main subwoofers reversing its phase and rolling it off at 80 Hz or so, this should protect the stage from any bass reinforcement and feedback issues like a cardioid system. Placing a sub behind the audience in the middle with the right delay and reverse phase should sort out those null problems shouldn't it. Placing a subwoofer against the side walls at 3O° pointing at the wall can achieve better coverage if the venue allows for that.
I will cover more complex setups in the rest of the series. As far as directing LF, if you roll off the lows of one of the subs, it loses the ability to control those frequencies.
@@DaveRat I'm not sure I'm getting you! You talking on stage you want it to cancel out that's the idea. Well the back of the room sub in studio, usually helps with reinforcement of bass because of the comb filtering from reflections and bouncing back at the listener. In a bigger venue I would have thought this would still apply!?
When you refer to rolling off at 80hz, and it being a subwoofer which typically rolls of highs at 80hz already. Anyway, to use multiple sound sources to create summations and cancellations as a result of interactions between the sound sources, the sound sources need to be reproducing frequencies in the freq range for the interactions to occur
In search of a sub that can handle 16 Hz for my 32' pipes (digital pipe organ) ideally in the 2000W range to pair with my 2 ways at 900 W. without breaking my back or bank. 😁
Why are PA system producers still use the bassreflex box for SUBS? Hunting for higher SPL will affect the quality of the sound, and it seems like it is more important to have a high SPL than high quality. The bass reflex need "time" to "start up" also after a hit there is a "reverb" after the signal. Going to different concerts I am amazed how bad many systems sounds. Big sub waves are "rolling around" just to die out slowly and the sound pic is a mess with a almost never ending big anddiffuse low bottom. The quality would improve drastic if people would use closed boxes. You loose SPL of course but music should be enjoyed.
Hmmm, sealed sub boxes are even slower due to back pressure in the box. But yes, many concerts use too much sub or have poor venue acoustics or poor setup designs
